Depending on what you want to be close to, here are some good building choices.
Cabana 9b is close to bus stop 1 and the main building with a short walk to the Dig Site (main pool) over the wooden bridge (Most convenient location and most preferred).
Cabana 8a is close to the Dig Site (and playground) and bus stop 4 with a short walk to the main building (Closest to the Pool).
Cabana 8b and 9a are in between the 2 above. 9a has a quiet pool (and is the old smoking optional building).
Ranchos 7b has a quiet pool, is close to the Dig Site and bus stop 4 with a bit longer walk to the main building. 7b is behind cabana 8a.
Casita 1 is attached to the main building and is very close to the restaurants.
Casita 3 has great courtyard and fountain views but you will have to walk or ride the internal shuttle to get to the pool.
Casita 5 has some nice fountain and lake views and is close to the Dig Site but farther from the main building. Close to bus stop #2.
Make your room request as soon as you make your reservation. Its never too early.
http://allearsnet.com/acc/cro1.htm